Apparatus for placing a liner in a vessel



March 30, 1965 APPARATUS FOR PLACING A LINER IN A VESSEL Filed Nov. 6, 1961 l l' l l Hl' H. M. LANG ETAL 2 Sheets-Sheet 1 HAROLD M. LANG DANIEL SILVERMAN INYENTORS.

ATTORNEY.

United States Patent 3,175,618 APPARATUS FOR PLACING A LINER IN A VESSEL Harold M. Lang and Daniel Silverman, Tulsa, Okla., assignors to Pan American Petroleum Corporation, Tulsa, Okla., a corporation of Delaware Filed Nov. 6, 1961, Ser. No. 150,398 4 Claims. (Cl. 16663) Our invention relates to apparatus for placing a metal liner inside a cylindrical vessel. More precisely, it concerns apparatus for expanding the liner with explosives to produce a fluid-tight fit of the liner against the inside of the vessel.

Briefly stated, this invention concerns apparatus for shock-forming liners in vessels, using an elongated explosive charge, confined in a substantially noncom-pressible material filling the liner. The apparatus of our invention expands the liner uniformly throughout its length avoiding the need for other finishing operations.

It is sometimes desirable to place a thin metal liner inside a pipe or other cylindrical vessel to cover a hole or leak that has developed. On other occasions a liner might be used to strengthen a weakened section or to provide a surface which is resistant to deterioration during normal useage of the pipe. The apparatus of our invention is useful in setting liners of the aforesaid type over such leaks or weakened areas.

FIGURE 1 is a view in cross-section of an embodiment of our invention adapted to operation on a cable for repairing leaks in oil well casing.

FIGURE 2 is another cross-sectional view, illustrating apparatus particularly suited to the lining of joints of pipe.

FIGURE 3 is a cross-sectional view of an embodiment of our invention for placing a liner in a liquid-filled section of a well.

FIGURE 4 is an elevation view of a part of the inside surface of a preferred form of inflatable bag.

Referring to FIGURE 1, the liner-setting apparatus a is positioned in a well adjacent hole 12 in casing 11. Metal sleeve 14, coated with layer 13 of either a cementing or a gasket material, is supported about receptacle 15 by rods 37. The receptacle is supported by cable 19 through closure and gland member 21. Cable clamp 22 retains the cable in the gland member. Clamp 23 secures the receptacle above the shoulder on closure member 21. Inside the receptacle, explosive charge 17, including detonator 18, is joined to conductors in cable 19 by electrical leads 20. It is essential that the receptacle zlmd explosive charge extend beyond the ends of the metal iner.

The apparatus illustrated in FIGURE 2 includes rod 24 along the longitudinal axis of receptacle 15. The rod provides stiffness and strength for the apparatus whereby long sections can be handled more conveniently in lining entire joints of pipe. This apparatus is particularly useful in lining pipe with a corrosion-resistant metal. A cementing or gasket material between the pipe and the metal sleeve might not be necessary if the ends of the lined pipe are protected to prevent the entry of fluid behind the liner. In the alternative, the liner may be coated with a cementing material as shown in FIGURE 1.

When a liner is to be set inside a pipe or vessel containing a liquid and it is not convenient to remove the liquid, apparatus of the type shown in FIGURE 3 may be used to great advantage. In this embodiment, the metal sleeve and shock-forming assembly are enclosed in inflatable bag 25. Housing 36 contains high-pressure gas source 32 which is controlled from the surface by way of electrical leads 27 in cable 19. Gas conduit 33 in mandrel 38 transmits gas from source 32 to the lower ice end of bag 25 via gas outlet 35. Pressure relief valve 28 in vent line 30 protects the bag from overinfiation by discharging gas in excess of that required to maintain sufiicient inflation to restrict liquids from that section of the well.

In placing a liner in a well as shown in FIGURE 1, metal sleeve 14 is placed over receptacle 15. The sleeve may be either cemented to the receptacle or supported by hooks on narrow strips or rods 37 held by clamp 23 and passing between the receptacle and sleeve. The outside diameter of the sleeve should be slightly less than the inside diameter of the pipe to be lined to avoid difficulty in lowering the assembly into the well. With the receptacle in place inside the sleeve, it is filled with a noncompressible material 16 such as water. Thereafter, explosive charge 17 and detonator 18 are lowered into the water-filled receptacle. Electrical leads 20 on the detonator are connected to conductors in cable 19. Closure 21 is engaged to seal the receptacle and enable the assembly to be supported by the cable. The final step in preparing the assembly is that of coating the metal sleeve with cementing material 13. Epoxy resin is a suitable cement. A layer between about /8 and A inch thick is usually adequate to fill any irregularities on the surface of the pipe and provide a continuous layer of cement. Glass fibers may be embedded in the resin to increase the strength of the cementing material. The resin preferably contains an activator to accelerate the hardening process after the sleeve has been placed. When a hightensile strength bond is not required between the liner and the pipe, a gasket material can be wrapped around the sleeve. Suitable materials for this are the elastomers and flexible plastics such as, for example, the synthetic rubbers, polytetrafluoro ethylene, and cellulose acetate butyrate.

The assembled apparatus is then lowered into the well until the metal sleeve is opposite hole 12 which is to be sealed. In some instances, it may be desirable to use a casing collar locator above the repair assembly to aid in positioning the assembly at the joint of casing to be repaired. With the assembly at the proper location, an electrical impulse is transmitted to the detonator. The shock wave from explosive charge 17 travels through the liquid and receptacle. The metal sleeve is shockformed into contact with the inside of the casing. With the explosive charge and confining liquid extending beyond the ends of the metal sleeve by a distance at least equal to the radius of the sleeve, a substantially uniform wave front contacts the sleeve from end to end. This produces a uniform expansion of the sleeve, thus eliminating the swaged sections at the ends of the liner produced by charges that do not extend beyond the ends of the sleeve.

Receptacle 15 may be made of rubber, plastic or thin metal. The receptacle is usually disintegrated by the explosive so that the debris falls to the bottom of the well where it will remain without interfering with other operations until it can be removed in a future clean-out operation. Portions of the receptacle retained by clamp 23 are removed from the well by withdrawing supporting cable 19.

The apparatus shown in FIGURE 2 is particularly suitable for lining pipe in a horizontal position. The explosive charge is spiraled about rod 24 with detonator 18 and electrical leads 20 near one end. Receptacle 15 is passed through metal sleeve 14, then fastened to the rod at one end with clamp 23 and filled with liquid or other noncompressible material. When filled, clamp 23 is placed about the other end of the receptacle. As in the casing liner setting assembly, the explosive charge and confining liquid should extend beyond the ends of the metal sleeve. Using rod 24 as a handle, the assembled 3 device canbe placed'inside the pipe to be lined. Suitable shielding must be provided to protect personnel and equipment from debris when the explosive is detonated.

Rod 24 may be covered with a deformable material such as rubber to reduce damage to it by the explosive.

The metal sleeve which is expanded by this apparatus may be a thin-walled tube of aluminum, lead, copper,

nickel, stainless steel, or other expansive material'which will provide a lining having the desired pnoperties. If desired, the metal sleeve can be coated on its exterior with a cement or gasket material. The heat transfer coeflicient andelectric-al conductivity are generally higher when a coating material is not used. Entire joints or pipe may be lined in this manner, then short liners placed inside the couplings to provide complete protection.

A liner ordinarily cannot be shock-formed in .a well containing liquid at thezone where the liner is to be "set. Thexapparatus of FIGURE 3 makes it possible to set a liner in this type of situation. Explosive charge 1-7 is wound around rubber jacket 34 covering mandrel 33. Detonator 18 with electrical leads 20 is coupled to the explosive. Receptacle is placed over the explosive charge and attached at one end with clamp 23. Metal sleeve 14 and supportrods 37 are slipped over the receptacle, then the receptacle is filled with liquid. Clamp 23' is placed on the other end to contain the liquid in the receptacle and anchor the upper ends of support rods 37. Electrical leads 29 pass between the end of the receptacle and rubber jacket 34, then into housing 36. Gas source 32 is installed in the housing whereby highpressure gas can be released into line 33. Electrical leads 27 connected to conductors in cable '19 provide means to control the discharge of gas from source 32. Housing closure and packing gland assembly 21 is attached, then inflatable bag 25 is placed around the assernbly and secured to housing 36 with clamp 31. The apparatus is then lowered into the well to a position opposite hole 12-, which is to be covered. At this time, an electrical signal is sent down cable 19 to release highpressure gas from source 32. The source may be a tank ct compressed hydrogen, nitrogen or other high vapor pressure gas, with a solenoid-operated valve to release gas into line 33 response to the electrical signal. An

alternative gas source is a cartridge of a propellant cornpositionsuchas smokeless powder or a rubber-ammonium perchlorate mixture which can be ignited. electrically. The released gas flows through'line 33 "and outlet 35 into the lower end of bag 25. As the bag i-sinfiated by the gas, liquids 26 are displaced from. that section of the well. When the bag is fully inflated, as shown in FIGURE 3, the pressure inside might continue to increase until pressure relief valve 28 in vent line 39 opens. This permits gas in excess of that required to inflate the bag to be exhausted through vent 29. This will prevent rupturing of the bag if an excessive volume of gas is released from source 32. A spring-loaded check valve can be used to retain a gas pressure in the bag slightly higher than the pressure of liquid 26 outside the bag.

7 With liquids displaced from the annular space between sleeve -14 and casing 11, an electrical signal can be sent down the cable and through leads 20 to detonate explosive charge 17. The shock wave produced by the charge is transmitted through the confining liquid to receptacle 15 and metal sleeve 14. The sleeve is expanded tightly against inflated bag 25, compressing it as a gasket between the casing and metal liner. Bag 25 is usually ruptured at the ends of the liner by the force of the explosive charge. In some instances, it might be desirable to provide small, circular charges to sever the bag cleanly at the ends of-the linen The assembly can be pulled and the well returned to production after the liner has been set. The inner surface of bagZ-S preferably has a wafile-like pattern to improve the sealbetween the metal sleeve and the bag; A packer element having this type of surface shown in US. Patent 2,681,706 Po'ttorf. FIGURE 4 shows the appearance of such an inner surface, provided with separated depressions 40 leaving intervening continuous ridges 41. Where the pressur-e of liquid 26 is high, the density of the gas inflating the bag will be substantial andresist the expansion of the sleeve against the bag. The depressions 40 in the wattle surface provide pockets for the gas so that theliner can expand against the ridges 41 in the wafile pattern and produce a fluid seal.

Although we have described electrical devices for detonating the explosive charge and inflating bag 25, it should be undenstood that these devices can be actuated by a tuner contained in the assembly.

The following description of a test illustrates the results whichcan be obtained with this apparatus. A section of annealed steel tubing 20 inches long having an outside diameter of 5 inches and an inside diameter of 4 inches was corrugated with eight folds toreduce its diameter. The section of tubing was covered with a sleeve of glass cloth having similar corrugations. The cloth sleeve extended beyond each end oi the steel tubing approximately 8 inches. These ends of the slceve were coated with a quick-setting plastic and. one end was plugged to provide a container for liquid. Three strands ot grain-per-fOdt Primaoord', 26 inches long, were :bundled together with a blasting capwat the center. This charge was suspended along the center of the corrugated tube with about 3 inches oi the charge extending beyond each end of the steel tubing into the plastic-coatedportion of the glass cloth. A catalyzed resintorming material was applied to the cloth behind the steel liner. Thereafter, the assembly was lowered into a joint of 5 /2 inch, 17 pound casing and the plastic-coated sleeve filled with water. After the charge had been detonated, the casing was cut open to examine the steel tubing. It was found to be expanded from end to end with only resin and glass cloth sepanating it storm the casing. The plastic-impregnated sleeve which extended beyond the ends of the steel tubing was disintegrated. The casing was bulged about 0.050 inch at the center of the sleeve and no enlargement was measured near the ends. The results of other tests with the casing surrounded by water indicated there is less swelling when the casing is surrounded by a non compressible material. The proper amount'of explosive to use depends upon the malleability of the metal sleeve, as well as the radius of the pipe or casing to be lined. Although we have described the use of cord-type explosives, any ot the common highwelocity explosives such as RDX, 'PETN, Tetryl, etc., can be used to prepare the elongated charges. It ordinarily makes little difference in the results whether the explosive charge is detonated at one end or in the middle; however, recoil from the explosion hight shiftthe position of the appza ratus when it is detonated at the end. For this reason, it is usually preterred to cap the charge near the middle.

The noncompressible material filling the between the explosive and the metal sleeve can be either a liquid or a solid. Water or a mineral oil such as kerosene are satisfactory liquids. In some instances it might be desirable to use a viscous or thixotropic fluid such as hydrated bentonite, napalm-gasoline gel, starch gel, oil water emulsions, and the like. Solids having low tensile strength can be used when it desirable to have a rigid assembly. Plaster of Paris is usually suitable, owing to its quick setting time and low strength.

While our invention has been described primarily with reference to the placement of liners in'pipe and well casing, it should be understood that it can be used to advantage in placing a metal liner in any vessel having a substantially cylindrical shape. I

We claim:

1. Apparatus for lining a hollow cylindricalmernber receptacle within said cylindrical member, and

means for detonating said charge to generate a shock wave which is transmitted by said incompressible substance as a radial force to the entire inner surface of said sleeve, thereby expanding it into contact with said member over the entire outer surface of said sleeve.

2. Apparatus according to claim 1 including also a layer of cementing material comprising a settable, partially-polymerized resin covering the outer surface of said sleeve, said resin being capable of solidifying and forming a high-tensile strength bond between said sleeve and said member.

3. Apparatus for lining a hollow cylindrical member containing liquid with minimum reduction of the internal diameter of said member, comprising an expansible cylindrical metal sleeve having an outside diameter slightly smaller than the inside diameter of said member,

an elongated explosive charge extending along the longitudinal axis of said sleeve,

a closed receptacle surrounding said charge and Within a substantially incompressible substance substantially completely filling the space within said receptacle surrounding said charge,

an inflatable bag surrounding said sleeve, charge, and

filled receptacle,

means for positioning said sleeve, charge, filled receptacle and bag within said cylindrical member,

remotely operable means for introducing a gaseous fluid into said bag to inflate said bag into contact with said cylindrical member and thereby substantially completely displace said liquid from the space between the outside of said sleeve and said member, and

means for detonating said charge to generate a shock wave which is transmitted by said incompressible substance as a radial force to the entire inner surface of said sleeve, thereby expanding it into contact with said member over the entire outer surface of said sleeve.

4. Apparatus as in claim 3, and wherein said liquid is present under substantial hydrostatic pressure, including also a vent line between the inside and outside of said inflatable bag, a pressure relief valve in said vent line adapted to prevent the pressure inside said bag from exceeding the pressure outside said bag by more than a preset amount, and

said inflatable bag having a waflle-like inner surface References Cited by the Examiner UNITED STATES PATENTS 1,981,525 11/34 Price 16649 2,214,227 9/40 English 16663 2,519,116 8/50 Crake 166--63 2,583,316 1/52 Bannister 166-46 2,681,706 6/54 Pottorf 166187 2,935,615 5/60 True 166-187 OTHER REFERENCES Gore, George L.: How Downhole Rubber Liners Can Help You, In World Oil, pp. 73-76, August 1, 1961.

CHARLES E. OCONNELL, Primary Examiner. NORMAN YUDKOFF, Examiner. 

1. APPARATUS FOR LINING A HOLLOW CYLINDRICAL MEMBER WITH MINIMUM REDUCTION OF ITS INTERNAL DIAMETER COMPRISING AN EXPANSIBLE CYLINDRICAL METAL SLEEVE HAVING AN OUTSIDE DIAMETER SLIGHTLY SMALLER THAN THE INSIDE DIAMETER OF SAID MEMBER, AN ELONGATED EXPLOSIVE CHARGE EXTENDING ALONG THE LONGITUDINAL AXIS OF SAID SLEEVE, A CLOSED RECEPTACLE SURROUNDING SAID CHARGE AND WITHIN AND SUPPORTING SAID SLEEVE, BOTH SAID EXPLOSIVE CHARGE AND SAID RECEPTACLE EXTENDING BEYOND THE ENDS OF SAID SLEEVE A DISTANCE AT LEAST EQUAL TO THE RADIUS OF SAID CYLINDRICAL MEMBER, A SUBSTANTIALLY INCOMPRESSIBLE SUBSTANCE SUBSTANTIALLY COMPLETELY FILLING THE SPACE WITHIN SAID RECEPTACLE SURROUNDING SAID CHARGE, MEANS FOR POSITIONING SAID SLEEVE, CHARGE, AND FILLED RECEPTACLE WITHIN SAID CYLINDRICAL MEMBER, AND 